Repeat biopsy of patients with acquired resistance to EGFR TKIs: implications of biopsy-related factors on T790M mutation detection.

• Cone-beam CT-guided repeat biopsy yielded high diagnostic specimen acquisition rate. • Biopsy-related features were associated with the detection of T790M mutation. • Target tumour size was an independent predictor of the T790M detection. • Biopsy targeting metastatic lung nodules might help detect the T790M mutation.